<template>
  <!-- 筛选区 -->
  <div class="sub-filter" v-if="filterData && !filterLoading">
    <div class="item">
      <div class="head">品牌：</div>
      <div class="body">
        <a
          href="javascript:;"
          v-for="brand in filterData.brands"
          @click="changeBrand(brand.id)"
          :class="{ active: brand.id === filterData.selectedBrand }"
          :key="brand.id"
          >{{ brand.name }}</a
        >
      </div>
    </div>
    <div class="item" v-for="item in filterData.saleProperties" :key="item.id">
      <div class="head">{{ item.name }}：</div>
      <div class="body">
        <a
          href="javascript:;"
          @click="changeAttr(item, p.id)"
          :class="{ active: item.selectedProp === p.id }"
          v-for="p in item.properties"
          :key="p.id"
          >{{ p.name }}</a
        >
      </div>
    </div>
  </div>
  <div v-else class="sub-filter">
    <XtxSkeleton class="item" width="800px" height="40px" />
    <XtxSkeleton class="item" width="800px" height="40px" />
    <XtxSkeleton class="item" width="600px" height="40px" />
    <XtxSkeleton class="item" width="600px" height="40px" />
    <XtxSkeleton class="item" width="600px" height="40px" />
  </div>
</template>
<script>
import { useRoute } from 'vue-router'
import { ref, watch } from 'vue'
import { findSubCategoryFilter } from '@/api/category'
export default {
  name: 'SubFilter',
  setup (props, { emit }) {
    // 1. 获取数据
    // 2. 数据中需要全部选中，需要预览将来点击激活功能。默认选中全部
    // 3. 完成渲染
    const route = useRoute()
    const filterData = ref(null)
    const filterLoading = ref(false)
    // 4. 分类发生变化的时候需要重新获取筛选数据，需要使用侦听器
    watch(
      () => route.params.id,
      newVal => {
        // 当你从二级分类去顶级分类也会拿到ID，不能去加载数据因为它不是二级分类的ID
        if (newVal && route.path === '/category/sub/' + newVal) {
          filterLoading.value = true
          findSubCategoryFilter(route.params.id).then(({ result }) => {
            // 品牌全部
            result.selectedBrand = null
            result.brands.unshift({ id: null, name: '全部' })

            // 销售属性全部
            result.saleProperties.forEach(p => {
              p.selectedProp = null
              p.properties.unshift({ id: null, name: '全部' })
            })

            filterData.value = result
            filterLoading.value = false
          })
        }
      },
      { immediate: true }
    )

    // 获取
    const getFilterParams = () => {
      const filterParams = {}
      const attrs = []

      filterParams.brandId = filterData.value.selectedBrand
      filterData.value.saleProperties.forEach(item => {
        const prop = item.properties.find(p => p.id === item.selectedProp)
        if (prop && prop.id) {
          attrs.push({ groupName: item.name, propertyName: prop.name })
        }
      })

      if (attrs.length) filterParams.attrs = attrs

      return filterParams
    }

    // 选择品牌
    const changeBrand = brandId => {
      if (filterData.value.selectedBrand === brandId) return

      filterData.value.selectedBrand = brandId

      emit('filter-change', getFilterParams())
    }

    // 选中属性
    const changeAttr = (item, attrId) => {
      if (item.selectedProp === attrId) return
      item.selectedProp = attrId

      emit('filter-change', getFilterParams())
    }

    return { filterData, filterLoading, changeBrand, changeAttr }
  }
}
</script>
<style scoped lang="less">
// 筛选区
.sub-filter {
  background: #fff;
  padding: 25px;
  .item {
    display: flex;
    line-height: 40px;
    .head {
      width: 80px;
      color: #999;
    }
    .body {
      flex: 1;
      a {
        margin-right: 36px;
        transition: all 0.3s;
        display: inline-block;
        &.active,
        &:hover {
          color: @xtxColor;
        }
      }
    }
  }
  .xtx-skeleton {
    padding: 10px 0;
  }
}
</style>
